Increased Volumetric Occlusion RegistrY
Endovascular intrasaccular embolization has been well established as a successful alternative to open surgical clipping since its inception in the early 1990’s. However, these historical publications only demonstrated the usefulness of platinum coils in the treatment of intracranial aneurysms. The first randomized control trial, the ISAT, demonstrated the superiority of the endovascular coiling using platinum coils over surgical clipping.
A more recent randomized control trial, which compared packing density of bare platinum coils against HydroCoils, a Hydrogel-coated platinum coil, the HELPS trial (HydroCoil Endovascular Aneurysm Occlusion and Packing Study) demonstrated that the recurrence rate and retreatment rate at 6-12 month follow up was superior in the HydroCoil arm. The overall recurrence rate was 25% in the bare platinum arm as compared to 15% in the HES arm with an overall retreatment rate of 4% in the platinum arm and 2.1% in the HES arm. This data was only the short-term follow up and complete 12-18 month follow up data is forthcoming. Although there may not be a significant difference in both arms of the study, it does demonstrate that the HES treated aneurysms had a lower percent recurrence rate with a 50% reduction in retreatments.
The HydroCoil system was developed to increase volumetric filling within the aneurysm sac. This hybrid platinum coil consists of hydrogel core with a platinum outer wind. (Figure 1)The Hydrogel material will expand over a predetermined time (20 minutes maximum) filling the dead spaces created within the aneurysm. To design a study to investigate the potential of increased volumetric filling of the HydroFill coil. The HydroFill coil is the next generation in the HydroCoil line which swells to approximately .022”. Pre-clinical reports have indicated that it has the same healing response as the existing HydroCoil line. This modified second generation coil system, although not a bioactive coil, can produce a high occlusion rate with low recanalization rates.
The focus of the study will be to determine if the HydroFill coil is safe and effective in treating all intracranial aneurysms. Also, to demonstrate if increased volumetric filling volumes utilizing the HydroFill coil, will create a more stable environment within the aneurysm sac to decrease recanalization and retreatment rates.
This will be a multi-center, multi-national study consisting of retrospective and prospective data collection of patients treated with the HydroFill coil system. The study PI will be Dr. Michael Kelly of the Royal University Hospital from Saskatchewan Canada.